For most of the 20th century, tuberculosis (TB) was in decline but since the mid 1980s, the trend has reversed and the number of TB cases globally now continues to increase. The "new" TB is characterized by HIV/-I-B co-infection and multiple drug resistant TB. In most parts of the world, TB and HIV epidemics are inextricably linked and call for an integrated approach of this dual epidemic. In developing countries, TB is the most frequent presenting opportunistic infection in people living with HIV/AIDS and TB is the leading cause of AIDS-related deaths. People fear TB, as it frequently heralds previously unsuspected HIV infection. The social stigma associated with the "new" TB is now compounded with the social stigma associated with HIV/AIDS. A better understanding of the changing social aspects of TB will be crucial for improved disease control. Clinical, biological and epidemiological interactions between TB and HIV have been studied extensively, but little is known about the psychosocial complexity of TB in HIV-infected individuals or about the social response of communities to TB in HIV/AIDS endemic areas. In this research project, a multidisciplinary team with clinical and operational research experience in the fields of behavioral science, epidemiology, sociology, ethnography, anthropology, infectious diseases and ethics propose to develop and validate a TB stigma scale for population-based assessment of TB stigma in the most southern part of Thailand, an area with a dual HIV/AIDS and TB epidemic. We will use the newly developed research instrument to obtain a better understanding of the key determinants of TB related stigma. We will measure the level of stigma experienced by TB patients in a cohort of active TB patients and correlate the stigma score to health-seeking behavior and adherence to TB therapy, two crucial elements of TB control. This project is the first attempt to integrate qualitative and quantitative research on stigma of TB in HIV endemic areas. The project will also initiate the collaboration between two universities (University of North Carolina, USA, and Prince of Songkla University, Thailand) to build research capacity on a subject of global importance.